The neuronal and muscular control of the organs in the urinary tract is very complex. These organs dynamically interact to allow production, transport, storage and elimination of urine in a safe, convenient manner. Disruption of these dynamic interactions can produce problems ranging from social embarrassment to severe urinary tract, or even systemic, infections that may lead to death. Interposed upon these dynamic-interactions is the influence of other organ systems and various substances; endogenous substances, such as purines and hormones, and exogenously administered substances, such as medications and other self-administered compounds. Our understanding of the nature of these interactions and how these influences alter the interactions will improve our ability to predict, interpret and correct abnormal functions in the urinary tract. This project is designed to study the autonomic and purinergic neurotransmitters involved in the control and dynamic interactions of the organs of the urinary tract. ln addition, this project will continue to develop and study chemical analogs useful in understanding the control mechanisms of the urinary tract and which may lead to clinically useful agents. This project is designed to determine the in vivo effects of purine agonists and antagonists, adrenergic agents and cholinergic agents on smooth muscle and neural activity of the lower urinary tract of the cat. Urinary bladder contractions and pelvic nerve activity will be measured. The data obtained from these studies should provide increased understanding of the way the organs in the urinary tract act and the role of purine neurotransmitter/neuromodulator substances in this system. This increased understanding can only improve our ability to predict, interpret and correct urinary tract dysfunction when it occurs.